The kinematic inverse problem for weakly laterally inhomogeneous anisotropic media

We derive a dynamic ray tracing system for seismic waves in an anisotropic medium. It consists of ten equations and can be solved numerically. For isotropic media it does not reduce to the DRT systems derived by other authors.     

Maximum likelihood estimation of Gutenberg-Richterb parameter for uncertain magnitude values

The maximum likelihood estimation of theb parameter in the Gutenberg-Richter relation is extended to the case of uncertain magnitude. An interval which contains the real unknown magnitude is used rather than the uncertain magnitude itself. The proposed approach is very flexible, it allows for the combination of the parts of a catalog of different quality into a single minimally biased set of recurrence parameters.On leave from the Institute of Geophysics, Polish Academy of Sciences, 00-973 Warsaw, Pasteura 3, Poland     

Liapunov instability of the hypoplastic model for soils

The hypoplastic constitutive model is known for its numerous application to the problems of soil mechanics and also for its excessive ratcheting. The paper shows that this deficiency can be interpreted as Liapunov instability in dynamic case. This is demonstrated with a simple one-dimensional swinger. Infinitesimally small as well as finite oscillations are analytically examined and the variability of stiffness upon a single cycle is considered. Several methods to circumvent the problem of ratcheting are discussed: implementation of ‘elastic’ range by means of so-called intergranular strain, usage of overlay modelling with parallel coupling of hypoplastic materials as originally proposed by Valanis in his endochronic theory and a special coupling of hypoplastic models based on comparison of partial stiffnesses.     

Three-Dimensional Geographically Weighted Inverse Regression (3GWR) Model for Satellite Derived Bathymetry Using Sentinel-2 Observations

Current trends of development of satellite derived bathymetry (SDB) models rely on applying calibration techniques including analytical approaches, neuro-fuzzy systems, regression optimization and others. In most of the cases, the SDB models are calibrated and verified for test sites, that provide favorable conditions for the remote derivation of bathymetry such as high water clarity, homogenous bottom type, low amount of sediment in the water and other factors. In this paper, a novel 3-dimensional geographical weighted regression (3GWR) SDB technique is presented, it binds together methods already presented in other studies, the geographically weighted local regression (GWR) model, with depth dependent inverse optimization. The proposed SDB model was calibrated and verified on a relatively difficult test site of the South Baltic near-shore areas with the use of multispectral observations acquired by a recently launched Sentinel-2 satellite observation system. By conducted experiments, it was shown that the proposed SDB model is capable of obtaining satisfactory results of RMSE ranging from 0.88 to 1.23[m] depending on the observation and can derive bathymetry for depths up to 12m. It was also shown, that the proposed approach may be used operationally, for instance, in the continuous assessment of temporal bathymetry changes, for areas important in the context of ensuring local maritime safety.     

Refinement of the Hardening Soil model within the small strain range

Acta Geotechnica - The popularity of the elasto-plastic Hardening Soil (HS) model is based on simple parameter identification from standard testing and empirical formulas. The HS model is...     

Statistical tools for maximum possible earthquake magnitude estimation

Several procedures for the statistical estimation of the region-characteristic maximum possible earthquake magnitude, m _max, are currently available. This paper aims to introduce and compare the 12 existing procedures. For each of the procedures given, there are notes on its origin, assumptions made in its derivation, condition for validity, weak and strong points, etc. The applicability of each particular procedure is determined by the assumptions of the model and/or the available information on seismicity of the area.     

Planning the Colca Canyon and the Valley of the Volcanoes National Park in South Peru

The economic development of the Rio Colca region and related infrastructure endangers the environment of the deepest canyon worldwide. The unique values of the Colca Valley and Canyon and its tributary Valley of the Volcanoes are summarised. They include a magnificent, deep section of the orogenic belt 100 km long, different geological formations, active faults, a variety of fold structures, young volcanoes, hot springs, geysers, several ecological zones and the largest condor habitat in the Andes. Based on the observed land use, development and regional planning, the threats and conflict areas are outlined. Studies performed by the Polish Scientific Expedition to Peru since 2003 add greatly to the knowledge of geology, landscape and pioneering biota development of the area and its importance to the world heritage of nature. They are aimed to give scientific background to the project of the Canyon Colca and Valley of the Volcanoes National Park. The article gives the proposed limits of the park and its buffer zones, categories of protection zones compatible with the SINANPE system of Peru and suggestions on tourist accessibility. The strict protection zone should cover the most inaccessible part of the area where human economic activity practically does not exist. Traditional farming and animal husbandry, wildlife, cultural tourism and some forms of adventure tourism will be allowed in the zone of special usage. The new park would strengthen the relatively poor system of the protected areas in the Arequipa Department, increase tourist attractiveness and determine constraints for sustained regional development. The expected actions of the park authority and local governments are specified.     

Sulphate Sources in the Sava and Ljubljanica Rivers, Slovenia, Inferred from Sulphur and Oxygen Isotope Compositions

Measurements were made of sulphur and oxygen isotope ratios of sulphate in some Slovenian rivers, lakes and tap waters. δ³⁴S ranged from −0.2 to + 13.3‰, δ¹⁸O ranged from +4.9 to + 13.6‰, and the sulphate content varied from 0.8 to 41.4 mg/L. Rivers flowing from the Julian Alps contain a very low amount of sulphate that is leached from a thin horizon of soil by rain. As confirmed by their low δ¹⁸O values, these sulphates do not enter the rivers directly in rain, but arise from biochemical cycling in the soil. The low δ³⁴S of this sulphate indicates that it originates from the oxidation of sedimentary sulphides. The evolution of sulphates along the river course was investigated for the Sava and Ljubljanica rivers. The variations observed in sulphate from the waters studied result from variations in the contribution of sulphates of different origin. Downstream the Sava River sulphate is depleted in the heavy isotopes of both sulphur and oxygen, with δ-values gradually tending toward the δ-values of groundwater sulphates in the watershed. In contrast, the δ-values of sulphate in the Ljubljanica River are almost constant and similar to those of sulphate in local groundwater. Introduction of water from Italian and Slovenian mines was recorded in the Soča River, where the lowest δ³⁴S value of sulphate sulphur (−0.2‰) was observed. In addition, the influence of sulphate from the oxidation of sedimentary sulphides was recorded in the Sotla River. No evidence was found for introduction of sulphate from factories.